Katie Holmes was spotted slipping solo into Jazz at Lincoln Center’s Rose Theater on Saturday to catch the closing matinee of Alan Cumming’s one-man “Macbeth.” The newly single mom was seen earlier the same day taking daughter Suri, 6, to Upper East Side cafe Via Quadronno. Cumming’s been shooting “The Good Wife,” then changing to his authentic Scottish accent to portray 15 characters in “Macbeth.” Cynthia Nixon and Julianna Margulies also had been spotted at the play.